Switch from log to tracing

[morr0ne]

This pr attempts to replace log with tracing in a way that is backwards compatible. However after staring at the code for a while I do start wondering if it's the best approach. Unfortunately the current implementation is kinda broken since log is called in init without being properly feature gated. I feel like it would be cleaner to just implement it in a somewhat backward incompatible way by removing the usage in init including the env_logger implementation and just add a log feature for users of the log crate. I don't think it make sense to have a breaking release just for logging but at the same time it something that should be done eventually.